Heated wire-cutting device



Aug. 1, 1961 PRIESTLY I Re. 25,016

HEATED WIRE-CUTTING DEVICE Original Filed Aug. 18, 1958 INVENT OR. 31 Fe/w P p/E5 n Y A TTORNEY United States Patent 25,016 HEATED WIRE-CUTTINGDEVICE Frank P. Priestly, Northridge, 'Calif., assignor to Link ResearchCorporation, Beverly Hills, Calif., a corporation of California No.2,916,595, dated Dec. 8, 1959, Ser. No. 755,492, Aug. 18, 1958.Application for reissue Feb. 11, 1960, Ser. No. 8,205

, 13 Claims. (Cl. 219-29) Matter enclosed in heavy brackets II ppears inthe orUnal patent but forms no part of this reissue specification;matter printed in italics indicates the additions made by reisue.

- vThis invention relates to a device for cutting material, such asexpanded polystyrene or the like, such material being a bubble-typeplastic made by inflating cells of polystyrene with air. There arevariations of such material as, for instance, thermosetting, solid,foamed, etc. These materials all have the same property, that of beingreadily cut by a heated member, as a blade or wire.

An object of the present invention is to provide an electrically heatedwire-cutting device in which the wire is.

the wireto an out-of-circuitposition as cutting pressure 2 .Theinvention also has for its objects to provide such means that arepositive in operation, convenient in use, easily installed in a workingposition and easily discon nested therefrom, economical of manufacture,relatively simple and' of general superiority and serviceability.

invention also comprises novel details of construcnovel combinationsandarrangernents of parts, iiliich'wilhmordfully appear in the course ofthe following description; However, the drawing merely shows andlthefollowing description merely describes, one embodiment of the presentinvention, which is given by way of illustration or exampl'eonly.

Ihthe drawing,"like reference characters designate similar-"parts inthe'several views.

FIG. 1 is *a broken longitudinal sectional view of a heated wire-cuttingdevice according to the present invention.

FIG. 2 is 'abr'oken bottom view.

"FIG. -3 is an' enlarged detailedview showing the wire meant in itsnormallout-of-circuit position. f'The-cutting"'devicethat is illustratedcom-prises, generally; a' base *5, a' goo seneck 6 carried by the base,means 7 for fiic'edly mountingth'e gooseneck, a wire means 8extendingbetween'thegooseneck and the top of the base fot outtingthrough material'M disposed upon the base,

means s to place 'the'wire 8 in electric circuit when pished'bysaidmaterialj rst base'f5has a preferably rectangular form with aflattop-"10"-' civer the 's urface of which a slab, sheet or blockjoimat'erial'M is 'adapted to be moved." The materialMj'as e'xplained,';ispireferablybf the that" iscapable'of 'alieated wire as the same ispushed against such wire, the cutting being accomplished i watch thein'aterial maybe a.

melting of the-expanses polystyrene or thelike of ICC The top 10 issupported by side walls 11, an interior space 12 thus being provided inthe base. Approximately centrally of its expanse, the top 10 is providedwith a hole 13 through which the lower end of the wire 8 passes. At oneend, the base is provided with a hole 14 imm diately beneath the top 10.

The base 5 is made of dielectric material to benonconducting,electrically, the base and walls thereof being thin, yet rigid, in thenature of sheet metal.

The gooseneck 6 is of generally U-shaped form, having a vertical leg 15connecting arms 16 and l7. The an 16 passes through the hole 14, as seenin FIG. 1, and the free end of the latter arm is provided with an ofisetor bend 18. It will be seen that arm 16 resides partly against the innerface of the base top 10 and extends partly beyond the base to bring theleg 15 considerably. rearward of the base.

The arm 17 is so spaced above the base top that ample space is providedin the U of the gooseneck for a piece of material M to move, ina widerange, along the base top. Said arm [16] 17 is preferably slightlyupwardly angled, as shown, the same being resiliently movable on thebend that joins said arm and the leg 15.

The means 7 is shown as a clip 19 that constitutes a socket for thebend'lfl at the end of arm 16. Said clip is preferably riveted, as at20, to the under face of the base top 10. Regardless how specificallydesigned, said clip aflixes the gooseneck 6 to the base 5 against bothendwise and rotational movement. The present "construction depends onthe means [9] 7, as will later be. seen, for preventing lateral movementof the gooseneck.

The wire means 8 comprises a wire 21 that is preferably formed ofNichrome or other high resistance material that becomes incandescentwhen a current of suitable potential is passed therethrough. One end ofsaid wire is provided with an eye 22 that is adapted to hook onto an endprojection 23 of the gooseneck arm 17. At. the other end, the wire 21 isprovidai with an insulator 24, preferably of ceramic material. Saidinsulator is either spherical or is providedwith a sphericalface which,with the wire passed through the hole '13, is directed toward the underface of top. 10.

The wire means 8 further includes a metal plate .25 that is aflixed tothe under face of base top 10 byrivet's 26 and is formed with anaperture or opening 27 ,through which the wire 21 passes and which isconsiderably smallor than the opening 13 in said top. Theopenings 13,and 27 are preferably concentric, as ,may best be seen in' FIG. 3. Aspherical seat 28 is formed in the plate 2 5, the hole 27 being centeredin seat and the insulator 24 normally centering itself in the seat sothe wire 21 passes through said hole 27 with uniform clearance all;around.

The means9 comprises a metal battery cell holder here shown as designedto hold two dry cells 30 and 31in; sideby-side relation in the interiorspace 12 of the base. Said holder 29 is aflixed to the base, as byrivets 32,3114; the same serves to clamp over the arm 16 offt'h'egooseneck and to be insulated therefrom by 'an insulator 53; The holder29 is provided with a terminal 34 for con- I nection with one electrodeof cell- 30 and a terminal 55 other electrode of cell 31.

I to the size of the gooseneck.- i I It will be n'otedlthattheresilience of 17 keepsthe wire-2l taut, and it is a simple matter tohooleand m hook the wire, the length of .which' is made The presentdevice contains no switchi as depends'wholly on making and breaking theelectric circuit through the'wire 21 upon whether or not the wiretouches the rim of hole 28. Since the insulator 24 normally centers onthe seat 28, the wire does not touch and the circuit is open. When thematerial -M is pushed against the wire 21, regardless of the directionof the push, the resilience of arm 17 allows the wire to becomelaterally displaced and a circuit is set up when the wire touches plate25. Release of such pressure allows the wire and its insulator tore-center on seat 28 to open the circuit.

' The circuit that is made, as above, passes through the gooseneck 6,clip 19, spring terminal 37, battery cell 31, terminal 35, holder 29,terminal 34, battery cell 30, spring terminal 36, plate 25, and wire 21.

Thus, the device provides automatic on and off switching which resultsin material cutting only when the wire isbeing'preesed by the materialM. Thus, as the different back and forth movements of the material aremade, the circuit opens and closes accordingly, greatly conserving thelives of the cells 30 and 31.

While the foregoing specification illustrates and describes what I nowcontemplate to be the best mode of carrying out my invention, theconstruction is, of course, subject'to modification without departingfrom the spirit and scope of my invention. Therefore, I do not desire torestrict the invention to the particular form of constructionillustrated and described, but desire to cover all modifications thatmay {all within the scope of the appended claims.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

l. A cutting device comprising a base having a surface on which-materialto be cut is adapted to be placed and moved therealong, a gooseneck,means fixedly mounting said gooseneck on said base, a resilient arm onsaid gooseneck being disposed in spaced relation to said base surface, aflexible heating wire extending between said base and the end ofthe'mentioned gooseneck arm, means to supply heating current to saidwire, and a shiftable connection between the base and thewire andconstituting aswitch in said circuit, the length of the wire being suchin relation to gooseneck arm spacing that the resilient arm maintainsthe wire in tension.

2. A cutting device comprising a base having a surface on which materialto be cut isadapted to be placed and moved therealong, a gooseneck,,means fixedly mounting said gooseneck on said base, a resilient arm onsaid gooseneck being disposed in spaced relation to said base surface, aheating wire having first and second ends, separably connected at thefirst end to the resilient gooseneck arm, an insulator on the second endof the wire,

around clearance and against which member the insulator is drawn by thetensioning means, and a source of electrio-current terminating at oneend at the apertured member and the other at the wire, lateral shift ofthe wire in the aperture to engage the apertured member closing thecurrent between said member and wire.

6. 'ln a'wire-cutting device according to claim 5, means formed in theapertured member to normally center .the insulator and the wire with thementioned all-around clearance.

7. In a wire-cutting device, a metal plate :provided with a seat andhaving an aperture centered in said seat, an end-biased heating 'wirepassed through said seat with electrical clearance with respect to theplate, and an insulator on the end of said wire and in seatingengagement with the seat under endwise bias of .the .wire to maintainsaid electrical clearance of wire and plate and to restore saidclearance after the wire has been shifted to electrically contact theplate.

8. In a wire-cutting device, a gooseneck composed of electricallyconducting materialhaving a free hooked end and having a second end towhich an apertured electrically conducting member is mechanicallyconnected but insulated therefrom, a wire having a first endelectrically connected to the hook end of thegooseneck and'havingasecond end extending through said apertured member with an insulator atthe end thereof, and current input terminals electrically connected tothe second end of the gooseneck and to said electrically conductingapertured member, the wire being of such length as to be under tensionwhereby the insulator tends to center the second end of the wire in saidaperture member out of electrical contact therewith, and lateralpressure upon the wire tendstto move it against the apertured member forestablishing an electrical circuit from said current input terminalsthrough the wire.

9. A cutting device comprising avsupport face, a wire cutter extendingfrom: a point above through said face,

' means to hold said wire in a normally predetermined an aperturedelectrically conducting member afiixed to the base and through theaperture of which said wire extends with the insulator biased towardsaid member by the resilient arm, means formed in said member tonormally center the insulator to hold the wire in clearance relationshipto the aperture, and electric-current input terminals, electricallyconnected to the first end of the wire and to the apertured member toestablish a wireheating circuit through the wire upon shift of the wireinto contact with the rim'of the aperture in the member.

3. A cutting device according to claim 2 in which the insulator isspherical and the means formed in the member comprises a seat in whichthe insulator is engaged by the biasof the resilient gooseneck arm. a

4. A cutting device according to claim 3 in which one of the inputterminals is connected to the gooseneck and the gooseneck iselectrically connected to the first end of the wire at all times. 1, ,l

5. Ina wire-,cutting-devicea heating wire having first and second ends,means tensioning the wire in the directionsof the first'end, aninsulator on the second endof the wire, an apertured current-passingmember through which the wire ,extends towards its secondend allpositionrelative to said face, means connecting one .end portion of said wireJoone side of a source .of electric current, and means connected to theother side ,ofsaid current source and in spaced proximity to theotherend portion of the wire and below said face, said latter meansbeing engageable by the wire only upon deflection of the latter from itsnormally predetermined position 10 close the electric circuit throughsaid wire to heat.the some for cutting throughva piece of work disposedon {the support face and moved over the surface thereof.

10. A cutting device comprising asupport face,. a .wl're cutterextending from a point above through said face, means to hold said wiretaut, means connectingoncend portion of said wire to one side of asource of.electric current, means connected to the other side ofsaidcurrent source and in spaced proximity to the other end portion ofthe wire and below said face, said latter means being engugeable by thewire upon deflection of the latter to close the electric circuitjhroughsaid .wire to heat 'the some for cutting through a piece of workdisposedon the support face and moved over the surface thereof, andmeans incorporated in: the last-mentioned meansto'automatically restorethe deflected wire to its mentioned spaced relation uponrelease fromdeflection thereof.

11. A cutting device comprising a support face, a wire cutter extendingfrom a point above .through saidfdcc; means to hold said wire taut,means-connectingone end portion: of said wire to one side of a sourceof'electric current, and means connected to the other side of saidcurrenrisource and in spaced encircling proximity ;to the displacementfrom its normal-tautly held positiomtoclosethe.=electric circuitthroughsaid wire to heapthe same for cutting. througha pieceiofworkdisposedlonjhe support face and moved overthe surface thcreof,.ond.mcms cm{ bodied in the last-mentioned means to automaticallymove the wire, when laterally displaced, back to its initialcircuit-open position upon release from displacement thereof.

12. A cutting device comprising a material-supporting face having anopening, a wire extending through said opening, means to hold the wiretaut with one end above the support face and the other therebelow,electrically conductive means adjacent to and below the support face andin spaced proximity to the wire at the lower end portion thereof whenthe wire is normally tautly held, and a source of electric currenthaving one side connected to the other end portion of the wire andhaving the other side connected to the last-mentioned means, said wireand electrically conductive means being engageable upon deflection ofthe wire from said normally-held position by a piece of material on thesupport face to close the electric circuit from said source through thewire to heat the same to a material-cutting temperature.

13. A cutting device comprising a material-supporting face having anopening, a wire extending through said opening, means to hold the wiretaut with one end above the support face and the other therebelow,electrically conductive means adjacent to and below the support face andin spaced proximity to the wire at the lower end portion thereof whenthe wire is normally tautly held,

a source of electric current having one side connected to the other endportion of the wire and having the other side connected to thelast-mentioned means, said wire and electrically conductive means beingengageable upon deflection of the wire from said normally-held positionby a piece of material on the support face to close the electric circuitfrom said source through the wire to heat the same to a material-cuttingtemperature, and means incorporated in the last-mentioned means toautomatically restore the deflected wire to its mentioned spacedrelation upon release from deflection thereof.

References Cited in the file of this patent or the original patentUNITED STATES PATENTS 2,221,330 Schneider Nov. 12, 1940 2,350,290 MooreMay 30, 1944 2,554,371 Marx May 22, 1951 2,587,775 Sheldon et a1. Mar.4, 1952 2,646,494 Fegan Dec. 13, 1955 2,727,128 Jaye Dec. 13, 19552,812,397 Taylor Nov. 5, 1957 2,916,595 Priestly Dec. 8, 1959

